The investigators completed a study for newly diagnosed glioblastoma that utilized bevacizumab, radiation therapy and temozolomide followed by 6 months of bevacizumab, irinotecan and temozolomide. In addition, the group at University of California at Los Angeles published a study with bevacizumab, radiation therapy and temozolomide followed by 12 months of bevacizumab and temozolomide for newly diagnosed glioblastoma. These two phase II studies reported acceptable toxicity and a suggestion of improved survival compared to historical controls, and led to two large phase III randomized, placebo controlled studies of the addition of bevacizumab for newly diagnosed glioblastoma patients. The current proposal builds on the encouraging results of the addition of bevacizumab to the standard therapy for newly diagnosed glioblastoma patients. Two critical questions remain- the role of bevacizumab maintenance and bevacizumab at the time of progression in a patient previously treated with bevacizumab at the time of initial diagnosis. In addition, a retrospective analysis of data collected at our center from patients with recurrent disease suggests that continuation of bevacizumab at the time of progression may improve overall survival in comparison with cessation of bevacizumab.